/*
 * $AIST_Release: 0.9.0 $
 * Copyright 2011 Information Technology Research Institute, National
 * Institute of Advanced Industrial Science and Technology
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *    http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package hadoop

import scala.collection.JavaConversions._
import org.apache.hadoop.io.Text
import org.apache.hadoop.io.BytesWritable
import util.JavaTypes.JIterable
import aggr.Deserializer.deserialize

class SCTextReducer extends SCReducerBase[Text, Text] {

  override def reduce(key: BytesWritable, values: JIterable[BytesWritable], context: Context): Unit = {

    val k = deserialize(keyType, Utils.copyToByteString(key))
    val data = values.map { v =>
      /* TODO: ほとんどのアグリゲータはKey毎に処理する。
       * その場合、keyをDeserializeするのは無駄である。
       * Key毎に処理するアグリゲータの場合にKeyをbyte列のま
       * ま処理できるように変更する。
       */
      (k, deserialize(valType, Utils.copyToByteString(v)))
    }

    aggr.aggregate(data) { case (k, v) =>
      context.write(new Text(k.toString()), new Text(v.toString()))
    }
  }
}

